Vat dye.



UNITED STATES PTENT OFFICE.

PAUL THOMASOHEWSKI, OF VOHWINKEL, NEAR ELBERFELD, GERMANY, ASSIGNOR TOFARBENFABRIKEN VORM. FRIEDR. BAYER & 00., OF ELBERFELD, GERMANY, ACORPO- RATION OF GERMANY.

var DYE.

Patented July 20, 1909.

Application filed March 16, 1909. Serial No. 488,675.

To all whom, it may concern:

Be lt'known that I, PAUL THQMASGHEW- sKI, doctor of philosophy, chemist,citizen of the German Empire, residing at Voh- 'winkel, near Elberfeld,Germany, have inlowing formula It can be obtained by condensing with theurea the 1-amino-4-beta-anthriminoanthraquinone (obtainable froml-nitrot-amino- I anthraquinone and beta chloro anthraquinone andreduction of the condensation product). v

In carrying out the process practically I can proceed as follows, theparts being by weight: A mixture of 6 parts ofl-amino-etbetaanthriminoanthraquinone, 10 parts of urea and 150 parts ofphenol is heated to boilin for 5 hours. Alcohol is added to the coldmelt and the crystalline precipitate is filtered off.

My new coloring matter thus obtained is a dark red crystalline powdersoluble with difficulty in the usual organic solvents with a violetcolor; and soluble in concentrated sulfuric acid with a violet-bluecolor. Upon treatment with hydrosulfite and-caustic soda lye an orangevat is obtained which dyes cotton violet-red fast shades.

I claim:

The herein-described new dyestufi' being a pyrimidone of the anthraceneseries 0btainable by condensing 1-amino-4-beta-anthriminoanthraquinonewith urea, which dyestufi is a dark red crystalline powder soluble withdifiiculty in the usual organic solvents and soluble in concentratedsulfuric acid witha violet-blue color; a vat being obtained from the newdye by treating it with hydrosulfite and caustic alkali, which vat dyescotton violet-red fast shades, substantially as. hereinbefore described.

- In testimony whereof I have hereunto set my hand in the presence oftwo subscribing witnesses.

Witnesses Orro Kome, AUG DICKBEN.

PAUL THOMASOIIEWSKI. [1 5.

Corrections in Letters Patent No. 928,891.

It is hereby certified that in Letters Patent No. 928,891, granted July20, 1909, upon the application of Paul Thomaschewski, of Vohwinkel, nearElherfeld, Gerfflany, for an improvement in Vat Dyes? errors appear inthe printed specification requiring correction, as follows: In lines12-23 the formula:

' co co it/kg N hii (Y C i I i should read CO I I W ag /v by) and inline 23 the article the should be stricken out; and that the saidLetters Patent'should be read with these corrections therein that thesame may conform to the record of the case in the Patent Oflice. lSigned and sealed this 28th day of September, A. D., 1909.

[SEAL] o. o. BILLINGS,

Acting Commissioner of Patents.

